[Left hemifacial flushing and sweating].
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Autonomic Fibers, Preganglionic↗
Biomedical subjects
H Tegetmeyer
Publications and source records attributed to H Tegetmeyer.
[Dynamics of the pupillary light reflex in unilateral Horner's syndrome].
BACKGROUND: The aim of this study was to characterise the changes of the dynamic pupillary light reflex in patients with unilateral Horner's syndrome by appropriate pupillographic parameters. METHODS: The dynamic changes of pupillary diameter in response to light flashes of 100 ms were recorded in darkness with two infrared video cameras in 15 patients. RESULTS: Significant changes in the pupillary light reflex of the affected side were observed only during the phase of redilatation. The decelerated redilatation was defined by the following parameters: (1) time parameters (percentage of redilatation after 4 s and after 5 s, time to reach 67% and 75% of redilatation) and (2) amplitude-adjusted velocity parameters (relative velocity at 67% and at 75% of redilatation). CONCLUSION: A slowed pupil redilatation in patients with Horner's syndrome can be detected also after short light flashes and is characterised by prolonged redilatation time parameters and reduced amplitude-adjusted redilatation velocity parameters.
Adolescent↗
[The influence of geometric visual illusions on saccadic eye movements].
BACKGROUND: The aim of this study was to investigate whether visually perceived length differences of Mueller-Lyer figures result in amplitude differences of saccadic eye movements along the figures. METHODS: Video recordings of eye movements were obtained from 35 healthy volunteers (aged 18 - 30 years) when scanning the endpoints of Mueller-Lyer targets. RESULTS: Saccades between the ends of lines with inward-pointing arrowheads had significantly greater amplitudes than saccades between the ends of lines with outward-pointing arrowheads. This bias was observed for both horizontal and vertical target orientations, and was maintained with a smaller amplitude, after fixation periods were extended from 1 s to 4 s. CONCLUSIONS: Changes in length perception by visual illusions correspond with changes in the amplitude of saccadic eye movements. Therefore, recordings of saccadic eye movements offer the opportunity to assess changes in visual object perception based on changes of central image processing at the cortical level.
Adolescent↗
[Leucocoria in childhood].
BACKGROUND: There are a number of conditions in infants and young children which produce a white reflex in the pupillary area, termed leucocoria. In cases of leucocoria, retinoblastoma has to be excluded without delay. METHODS: We analysed data from consecutive children who were presented to our hospital because of leucocoria between January 1999 and June 2005. The analysis was performed by methods of descriptive statistics. RESULTS: Leucocoria was found in 83 eyes of 58 children. Leucocoria was caused in most cases by congenital cataract (35 %), followed by malformations (18 %) (persistent hyperplastic primary vitreous, coloboma, disc anomaly, combined developmental abnormalities), hereditary vitreoretinal disorders (13 %), retinopathy of prematurity (12 %), trauma-associated diseases (8 %). Five children suffered from retinoblastoma (6 %). Following in frequency were inflammatory disorders (5 %) and Coats' disease (2 %). DISCUSSION: Several ocular conditions of childhood can clinically cause leucocoria. Knowledge of the clinical features that serve to differentiate retinoblastoma from simulating lesions may assist the clinician in arriving at the correct diagnosis.
Cataract↗
[Diabolic injury with the localization of foreign bodies in the apex of the intraorbital region ].
BACKGROUND: Air-gun injuries with localisation of the pellet at the apex of the orbital cavity can cause difficult decisions in diagnostics and therapy, especially if you decide to retain the foreign body. METHODS: We report on a 14-year-old boy who was hit by an air-gun pellet. The foreign body went into the left orbit without damaging the globe or the optic nerve. RESULTS: The visual acuity was 1.0, the mobility was only slightly disturbed. A systemic therapy with antibiotics and corticosteroids could stop a series of relapses very well. CONCLUSIONS: Foreign bodies of the orbit can be retained if it is possible to deal with the surrounding reactions properly by conservative therapy.
Adolescent↗
Smooth pursuit eye movements in patients with ocular motor nerve palsies: a preliminary report.
The trajectories, velocity, and co-ordination of smooth pursuit eye movements were investigated in 30 patients with ocular motor nerve palsies (including palsies of cranial nerves III, IV and VI). The recordings of horizontal and vertical eye movements were obtained by video-oculography under monocular viewing conditions. During the recordings, horizontal, vertical, and oblique target movements of 10 degrees /s constant velocity were presented to the subjects in succession. In contrast to normal subjects, smooth pursuit eye movements in patients with ocular nerve palsies showed considerable differences in dependence on the fixating eye. The smooth pursuit gain of the paretic eye was reduced for eye movements in the pulling plane of the paretic muscle. When viewing with the paretic eye, the tracking of the target was achieved by a series of refixation saccades, which also occurred in the occluded normal eye. Consequently, the sound eye position overshot the target. The transition from a smooth to a saccadic pursuit pattern was accompanied by a spatial deviation of the eye movement trajectories from the path of the fixation target.
Electrooculography↗
Influence of visual signals on the coordination of spontaneous eye and head movements in infant rabbits.
Horizontal angular movements of eye, head, and trunk were simultaneously recorded in spontaneously behaving unrestrained rabbits in the period after postnatal eye opening. The recordings were performed in daylight as well as in darkness. A crosscorrelation analysis of the velocities of eye in head and of head to trunk during periods of exploratory activity showed that the resulting crosscorrelation functions were mainly determined by the correlation of coupled saccadic movements of eye and head. Already at the end of the third postnatal week, the maxima of the crosscorrelation functions were higher and their time shifts were shorter for movements in light than for movements in darkness. These observations suggest that the stronger coupling of saccadic eye and head movement velocities in response to light reflects a light-induced increase in the activity of premotor neurons of the superior colliculus.
Animals↗
Spatial orientation of extraocular muscle EMG responses to tilt in the rabbit during postnatal development.
Unanaesthetized pigmented rabbits 2-45 days of age were gradually tilted (15 degrees steps) over 360 degrees around three orthogonal body axes. The multiunit electromyogram activity of superior rectus (SR) and superior oblique (SO) extraocular muscles was recorded with chronically implanted pairs of fine wire electrodes after each tilt step. The integrated EMG activity of the extraocular muscles in response to static tilt stimulation was trigonometrically related to tilt angle in all age groups. Each eye muscle was characterized by a typical locus of tilt positions which resulted in maximum integrated EMG activity. This locus was described by a vector of tonic vestibular activation (TVA) within the head coordinate system. The orientation of these TVA vectors within the coordinate system of the rabbit's head and, therefore, the coordination of tonic eye muscle activation in response to the position of the animal in the gravitational field did not change with postnatal age in the rabbit. Therefore, eye muscles are already capable of responding to static vestibular stimulation for the stabilization of gaze when visual information becomes available to the rabbit pups. The EMG responses to static tilt stimulation were principally determined by the scalar product of the gravity vector and the muscle's TVA vector. The response of the extraocular muscles to this effective gravitational stimulus was unchanged during the postnatal development of the rabbit: excitatory stimuli resulted in an approximately linear increase of the integrated EMG activity, inhibitory stimuli resulted in a smaller decrease to a minimum value. The correlation between the effective strength of excitatory gravity stimuli and the EMG activity of the extraocular muscles increased significantly at the time of postnatal eye opening. Since the strongest responses of SR and SO to static tilt were observed in intermediate roll-pitch positions that correspond closely to the planes of the vertical semicircular canals, a common reference frame for the cooperation of maculo-ocular and ampullo-ocular reactions is suggested.
Acceleration↗
Effects of an early postnatal hypoxia on the development of spontaneous head movements in rabbits.
The early detection of minor brain dysfunctions resulting from perinatal hypoxia is very important since the prognosis of the affected children can be substantially improved by a prompt treatment. Therefore, this paper deals with the influence of an early postnatal hypoxia on the postnatal development of spontaneous head movements and the influence of the visual system on head movements in normal and hypoxic disturbed ontogenesis. Head movements were recorded in 12 unrestrained spontaneously behaving alert rabbits from 6 litters with the sensor coil technique. One rabbit of each litter was exposed to a single acute hypoxia (FiO2 = 0.05) for 3 h at the 1st day of life. The siblings were regarded as a control group. The most important characteristic of the postnatal development of the head movements is the forming of horizontal saccadic movements during the second postnatal week and their perfection by an increase in mean velocity up to the 20th postnatal day. The early postnatal hypoxia leads to a decrease of the mean velocity of saccadic head movements. But this is only true if the rabbits have open eyes. Blind-folding the rabbits of the control group during the recordings was followed by a decrease of the mean velocity (14th and 20th postnatal day) and the amplitude (at the 20th postnatal day) of the saccadic head movements. In contrast to the non-hypoxic rabbits, blind-folding had no perceptible influence on head movements in hypoxic rabbits until the 3rd postnatal week. Our results suggest that early postnatal hypoxia causes a
Animals↗
[The postnatal development of EMG reactions of limb muscles to free fall stimulation. I. Studies in normal rabbits].
The ontogenetic development of the vestibulospinal reaction following the free fall was studied in 11 rabbits ("Deutscher Riese") 8 to 20 days old by means of myographical recordings (EMG) synchronously derived from 3 muscles (M. triceps brachii caput lateralis, M. brachialis, M. quadriceps femoris vastus lateralis) by chronically implanted steel wire electrodes. With increasing age, rabbits show a sustained rise of EMG activity during fall and develop the ability to change the generated EMG activity under the condition of repeated stimulation. It is concluded, firstly, that more typical EMG reactions are produced with growing age, and secondly, that the ability to modify the intensity of the response to repeated free falls increases during postnatal development.
Animals↗
[The postnatal development of EMG reactions of limb muscles to free fall stimulation. II. Studies of early postnatal hypoxic-burdoned rabbits].
12 rabbits ("Deutscher Riese") were exposed to a hypoxic atmosphere (FiO2 = 0.05) for 3 h at their 1st day of life. At the 7th or 13th day of life, steel wire electrodes were chronically implanted into 3 leg muscles in order to record the electromyograms (EMG). The myographic activity was derived during free fall (height of drop = 0.5 m) until the age of 20 days. The quantitatively analysed EMG data were compared with corresponding data of undisturbed growing control animals. Using various EMG parameters, a quantitative separation of hypoxic animals from the controls was successfully done by a discriminant analysis, the animals being 8 and 20 days of age, respectively. It can be concluded that 1. already a single perinatal hypoxic load influences the supraspinal motor system permanently at least up to the age of 20 days, and that 2. this supraspinal influence on the investigated vestibulospinal reaction changes with increasing age of the rabbits.
Aging↗
[Morphometric studies of the postnatal development of the articular system of the bulbus oculi in rabbits].
The postnatal development of oculo-motor reactions is probably caused partly by changes of the passive mechanical properties of the bulb joint system. The YOUNG's elasticity modulus seems to be a suitable parameter to describe these changes. For its calculation, the length and the cross section area of the extraocular muscles as well as the dimensions of the ocular bulb are necessary. Moreover, the bulb mass is needed to analyse the inertia of the bulb during each movement. The postnatal growth of these parameters was investigated and, by means of the linear regression analysis, we looked for the best fitted mathematical expression. By this, there is the possibility to estimate the morphological data for detailed longitudinal analysis of changes of the oculo-motor function if the age and the body mass, are known.
Animals↗
A follow-up study of perinatally hypoxic rabbits.
Rabbits, surviving a severe 3-hours-lasting hypoxia (FiO2 = 0.05) during the 1st day of life, grew up together with their littermates. In animals aged 10 and 20 days, respectively, the vestibular induced tonic eye deviations were investigated during tilting around the three orthogonal body axes. The spontaneous head-body-motor coordination was analysed by means of a search coil technique in 14 days old rabbits. Perinatally hypoxic rabbits exhibit a compensation of initially reduced torsional tonic eye deviation and an overcompensation of the vertical ones at the 20th postnatal day in comparison to controls. Moreover, we found reduced amplitudes and velocities of spontaneous head saccades in perinatally hypoxic animals 14 days old. We assume a retarded development of the neuronal nets of the brain stem reticular formation in the hypoxic rabbits accompanied by an insufficient visuo-vestibular interaction.
Aging↗
Changes of EMG activity patterns of extraocular muscles and the tonic control of eye position during the postnatal development of the rabbit.
The motor activity patterns of the rectus superior and obliquus superior extraocular muscles of the rabbit in response to static tilt stimulation were studied by electromyography in the unanaesthetized animal during postnatal development. During the first postnatal week the eye muscle activity showed a phasic pattern with continuous fluctuations of the activity level. The main postnatal decrease of the variability of EMG activity level occurs in the rabbit during the second week of life. Thereby, a constant tonic EMG activity of the extraocular muscles during static tilt stimulation was achieved from the third postnatal week onwards. The ability of stabilizing the eye position in space by this developmental process is an important prerequisite for the normal development of an effective visual orientation of the rabbit after the postnatal opening of the eyes.
Aging↗
On the development of eye-head coordination in freely moving rabbits during the first month of life.
Eye and head movements were recorded in unrestrained spontaneously behaving alert rabbits during the first postnatal month with the search coil technique using phase angle detection in a rotating magnetic field. In the first postnatal week saccadic eye movements occurred seldom and were of small amplitude. After an increase in frequency, amplitude, and velocity of saccadic eye movements the rabbits achieved an effective intersaccadic stabilization of eye position in space during active movements at the end of the third postnatal week. However, the characteristic adult pattern of alternate saccadic eye movements accompanied by head movements and slow eye movements compensating head movements was already observed at the time of eye opening (around the 12th postnatal day). Saccades initiated while the head was stationary occurred for the first time during the second postnatal week. It is concluded that the coordination and the dynamics of active eye and head movements in postnatally developing rabbits already considerably contribute to the reduction of retinal image slip velocity at the time of the postnatal opening of the eyes.
Aging↗
[Postnatal development of static vestibulo-ocular reactions in the rabbit--electromyographic studies].
The changes in the electric activity of the extraocular muscles as a consequence of static tilt stimulation were investigated in rabbits of different postnatal ages by the registration of the electromyogram. The postnatal development of the tonic vestibulo-ocular reflex in the rabbit runs parallel with the transition from an irregular fluctuating eye muscle activity during the first postnatal days to a constantly tonic muscle activity depending on the tilt position.
Animals↗
Tonic vestibular control of eye position in postnatal developing rabbits.
With head and body fixed, 22 rabbits aged between 1st and 54th postnatal day were rotated step by step in 47 experiments over 360 degrees around their transverse and their longitudinal body axis, and in some cases around the horizontally placed dorsoventral body axis, too. The position of one eye, marked by burning a cornea stamp, was photographed after each rotation step. The observed eye positions in different tilt positions are always a consequence of combined horizontal, vertical and rolling eye movements, though compensatory counterrolling and compensatory vertical deviations of the eye predominated. During postnatal development in the rabbit, typical eye movement patterns as a course of eye positions during step by step 360 degrees rotation were formed until the second month of life. By reason of the polarization directions of their sensory cells, utricular maculae are obviously able to generate an innervation pattern for the tonic eye muscle contractions causing the observed eye movements.
Age Factors↗